System and method of using thermal and electrical conductivity of tissue

ABSTRACT

A system for planning, performing and/or evaluating the effectiveness of a therapeutic treatment of a target tissue includes at least one of a thermal conductivity probe including a microprobe sensor configured and adapted to measure a thermal conductivity in the target tissue in at least one direction or an electrical conductivity probe including a microprobe sensor configured and adapted to measure an electrical conductivity in the target tissue in at least one direction. The system further includes a multimeter operatively connected to at least one of the thermal conductivity probe or the electrical conductivity probe, the multimeter being configured and adapted to deliver energy to at least one of the thermal conductivity probe or the electrical conductivity probe, and a computer operatively connected to the multimeter.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. patentapplication Ser. No. 12/016,761, filed Jan. 18, 2008, which claimspriority to U.S. Provisional Application Ser. No. 60/881,238, filed onJan. 19, 2007, the entire contents of each of which are incorporated byreference herein.

BACKGROUND

1. Technical Field

The present disclosure relates to electrosurgical instruments, systemsand methods of using the same and, more particularly, the presentdisclosure relates to systems and methods for sensing and usingdirectional attributes of tissue.

2. Discussion of Related Art

Thermal therapy, such as Radiofrequency (RF) ablation, is an effectiveprocedure for the treatment of certain tumors and the like. However, theoutcome of said thermal therapies may be unpredictable and inconsistent.The increasing use of thermal therapy in the treatment of biologicaltissue and the like necessitates an accurate determination and athorough understanding of the unpredictability and inconsistenciesassociated with thermal therapy. It is believed that thermalconductivity and electrical conductivity of biological tissues is afactor in contributing to the unpredictability and inconsistenciesassociated with thermal therapy.

It has been seen that biological tissue has different thermal and/orelectrical conductivities in different directions. Thermal conductivityof biological tissues is dependent on the particular type of biologicaltissue and on the composition of the biological tissue. Differentbiological tissues exhibit different and/or unique thermalconductivities based on factors such as tissue density, tissuehydration, vascularization, age, direction and distance to major bloodvessels, etc. Additionally, different biological tissues may exhibit adifferent and/or unique thermal conductivity in various directions fromone another.

Electrical conductivity is not only determined by tissue type andcomposition, but also by other externally applied physical and chemicalinfluences during thermal treatment, such as, for example, temperatureinducement and saline pretreatment. An accurate knowledge of a change inthe electrical conductivity of the target tissue, due to temperatureelevation, may be a factor in predicting ablation area/volume, RF powercontrol, and optimization of the cyclic RF power delivery. Knowledge ofelectrical conductivity as a function of salinity level of the targettissue may be another factor in predicting ablation area/volume, RFpower control, and optimization of the cyclic RF power delivery.

These differences in thermal and electrical conductivity may affect theshape of the treatment zone during thermal therapies. Knowledge of thethermal and electrical conductivity of the tissue may also be used toenhance the resolution of modern imaging modalities (fluoroscopy, X-ray,CT scan, MRI, Ultrasound, etc.). Accordingly, sensing, measuring andinterpreting these values and differences in thermal and/or electricalconductivities would be useful in assisting in the planning andperforming of thermal therapy procedures.

SUMMARY

A system for planning, performing and/or evaluating the effectiveness ofa therapeutic treatment of a target tissue is provided. The systemincludes at least one of a thermal conductivity probe including amicroprobe sensor configured and adapted to measure a thermalconductivity in the target tissue in at least one direction or anelectrical conductivity probe including a microprobe sensor configuredand adapted to measure an electrical conductivity in the target tissuein at least one direction. The system further includes a multimeteroperatively connected to at least one of the thermal conductivity probeor the electrical conductivity probe, the multimeter being configuredand adapted to deliver energy to at least one of the thermalconductivity probe or the electrical conductivity probe, and a computeroperatively connected to the multimeter.

The system may further include a power supply operatively connected toeach of the thermal conductivity probe and the electrical conductivityprobe. The power supply may be configured and adapted to supply power toeach of the thermal conductivity probe and the electrical conductivityprobe. The system may further include a therapeutic treatment deviceconfigured and adapted to deliver therapeutic energy to the targettissue. The energy delivery setting of the therapeutic treatment devicemay be determined based on at least one of the thermal or electricalconductivity measurements.

The system may further include an indicator for providing an indicationin response to a predetermined value of at least one of the thermal orelectrical conductivity measurements, whereby critical tissue can bekept from undue harm.

Also provided is a method of planning, performing and/or evaluating theeffectiveness of a therapeutic treatment of a target tissue. The methodincludes measuring at least one of the thermal or electricalconductivity of a target tissue in at least one direction, inputting atleast one of the measured conductivities of the target tissue for eachdirection into a modeling environment, creating a representation of atreatment zone for the target tissue from the modeling environment, andselecting at least one therapeutic treatment device, at least one energysetting for the therapeutic treatment device, and an orientation for thetherapeutic treatment device based on the representation of thetreatment zone for the target tissue.

The method may further include measuring both thermal and electricalconductivity of a target tissue in at least one direction. Additionally,the method may include treating the tissue using the at least onetherapeutic treatment device. The method may also include measuring atleast one of the thermal or electrical conductivity of a target tissuein at least one direction following treatment of the target tissue. Themethod may further include measuring at least one of the thermal orelectrical conductivity of a target tissue in multiple directions.

The method may further include the step of providing an indication inresponse to a predetermined value of at least one of the thermal orelectrical conductivity measurements, whereby critical tissue can bekept from undue harm.

A method of enhancing an image is also provided. The method includesmeasuring at least one of a thermal conductivity or an electricalconductivity of a target tissue in at least one direction, inputting atleast one of the measured conductivities of the target tissue for eachdirection into a modeling environment to create at least one resultingimage, and combining the at least one resulting image to produce anenhanced image. The imagining technique may include at least one offluoroscopy, X-ray, CT scan, ultrasound, or MRI.

Also provided is a system for planning, performing and/or evaluating theeffectiveness of a therapeutic treatment of a target tissue, includingat least one of a thermal conductivity probe or an electricalconductivity probe. Each of the thermal conductivity and the electricalconductivity probes may include at least one microprobe sensor, and themicroprobe sensors may measure a respective thermal conductivity orelectrical conductivity of the target tissue. The system furtherincludes a multimeter operatively connected to at least one of thethermal conductivity probe or the electrical conductivity probe, themultimeter being configured and adapted to deliver energy to at leastone of the thermal conductivity probe or the electrical conductivityprobe, and a computer operatively connected to the multimeter. Eachmicroprobe sensor may measure a respective property in at least onedirection.

The system may further include a power supply operatively connected toeach of the thermal conductivity probe and the electrical conductivityprobe. The power supply may power each of the thermal conductivity probeand the electrical conductivity probe. The system may further include atherapeutic treatment device for delivering therapeutic energy to thetarget tissue. The energy delivery setting of the therapeutic treatmentdevice may be determined based on at least one of the thermal orelectrical conductivity measurements gathered by the respective thermaland electrical conductivity probes.

DETAILED DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure are disclosed herein withreference to the drawings, wherein:

FIG. 1 is a schematic perspective view of a conductivity sensing systemaccording to an embodiment of the present disclosure;

FIG. 2 is a schematic illustration of an embodiment of a thermalconductivity sensing device of the conductivity sensing system of FIG.1;

FIG. 3 is a schematic illustration of an embodiment of an electricalconductivity sensing device of the system of FIG. 1;

FIG. 3A is an enlarged view of the indicated area of detail of FIG. 3;

FIG. 4 is a schematic illustration of the conductivity sensing circuitsof FIG. 1, shown mounted on electrosurgical devices in operativeassociation with a target tissue; and

FIG. 5 is a perspective view of a distal end of an electrosurgicaldevice of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

The devices, systems and methods of the present disclosure provide forthe sensing of directional attributes of tissue in order to assist inplanning, performing and/or evaluating the effectiveness of thermaltherapy procedures. In the drawings and in the description whichfollows, the term “proximal”, as is traditional, will refer to the endof the system, or component thereof, which is closest to the operator,and the term “distal” will refer to the end of the system, or componentthereof, which is more remote from the operator.

As used herein, the term “thermal treatment” is understood to includeand is not limited to treatment using radio-frequency (RF), laser,microwave, cryoablation ultrasound, HIFU, and electromagneticstimulation of micro- and nano-particles.

1. Electrosurgical System

With reference to FIG. 1, in accordance with an embodiment of thepresent disclosure, a conductivity sensing system for sensingdirectional attributes of tissue in order to help in planning,performing and evaluating the effectiveness of thermal therapy, ablationand other electrosurgical procedures, is generally designated as 100.System 100 includes a sensing device 200 in the form of a thermalconductivity probe, a power source “PS” connected to or connectable todevice 200, a multimeter “M” or impedance analyzer “IA” connected to orconnectable to device 200 and a computer “C” connected to or connectableto multimeter “M”. System 100 may further include anotherelectrosurgical device 300 in the form of an electrical conductivityprobe, connected to or connectable to multimeter “M”, an impedanceanalyzer “IA” or the like, or other suitable devices.

As seen in FIG. 1, thermal conductivity probe 200 includes a first pairof bonding pads 202 electrically connected to or electricallyconnectable to a power source “PS”, and a second pair of bonding pads204 electrically connected to or electrically connectable to multimeter“M”. Electrical conductivity probe 300 may include a pair of bondingpads 304 electrically connected to or electrically connectable tomultimeter “M”. The aspects of the present disclosure should not be readas limited to the embodiments of thermal conductivity probe 200 andelectrical conductivity probe 300 described herein. Any probe or probescapable of acquiring directional attributes of tissue have beenenvisioned for use with aspects of the present disclosure. For a moredetailed discussion thermal conductivity probe 200 and electricalconductivity probe 300, as shown, including methods of manufacture anduse, please refer to commonly owned U.S. patent application Ser. No.12/016,754, now U.S. Pat. No. 7,951,144, entitled “Thermal andElectrical Conductivity Probes and Methods of Making the Same”, theentire contents of which are incorporated by reference herein.

As seen in FIG. 4, in an alternate embodiment of the present disclosure,conductivity sensing system 100 is incorporated into an electrosurgicalsystem 400 for performing electrosurgical procedures. Electrosurgicalsystem 400 includes a generator “G”, for example, an AC or DC powersupply, a radiofrequency generator providing energy at frequenciesbetween several kilohertz to several hundred megahertz, or any othersuitable power source. Generator “G” may have a power output rangingfrom several watts to several hundred watts, depending on the clinicalneed. Generator “G” may have control devices to increase or modulatepower output as well as readout and display devices to monitor energyparameters such as voltage, current, power, frequency, temperature,impedance, etc., as appreciated by one skilled in the art. Other typesof power sources and/or generators are contemplated, e.g., including andnot limited to resistive heating units, laser sources, or microwavegenerators. Generator “G” includes power source “PS” capable ofsupplying constant power to microprobe sensor 220. Other types of powersources and/or generators are contemplated, e.g., including and notlimited to resistive heating units, laser sources, or microwavegenerators.

2. Method of Using Thermal Conductivity

Knowledge of the thermal conductivity of the tissue permits a surgeon toadapt the treatment based on the thermal conductivity of that tissue.For example, a measurement of a relatively low thermal conductivitywould indicate that, during therapeutic treatment of tissue, thermalenergy would travel relatively less in the direction in which therelatively low thermal conductivity measurement was made as compared toother directions. Likewise, a measurement of a relatively high thermalconductivity would indicate that, during therapeutic treatment oftissue, thermal energy would travel relatively more in the direction inwhich the relatively high thermal conductivity measurement was made ascompared to other directions.

As such, once the thermal conductivity of the target tissue “T” isdetermined, a selection of a suitable electrosurgical ablation needle,for example, associated power parameters, and relative orientations ofablation needle placement may be determined, based thereon, for thetherapeutic treatment of the target tissue “T” by the electrosurgicalablation needle. The thermal conductivity of the target tissue “T” maybe acquired intermittently throughout the treatment of the tissue. Inthis manner, a surgeon may monitor the effects of the treatment on saidtarget tissue “T” and the surrounding tissue.

Thermal conductivity probe 200 is adapted to measure thermal conductanceK_(eff) as represented by the following equation as commonly known inthe field:

$K_{eff} = {{K\left\{ {1 + \frac{{n\left\lbrack {\left( {\rho \; c} \right)_{b}\pi \; r_{b}^{2}\overset{\_}{V}\cos \; \gamma} \right\rbrack}^{2}}{\sigma_{\Delta}K^{2}}} \right\}} + q -_{met}}$

where:

-   -   K_(eff) is the “effective” tissue conductance which is measured.        K_(eff) is the combination of conduction (due to intrinsic        thermal conductivity) and convection (due to perfusion);    -   K—is tissue conductance in the absence of perfusion;    -   n—is the number of blood vessels;    -   p—in (pc)_(b) is the density of blood;    -   c—in (pc)_(b) is the specific heat of blood;    -   r_(b)—is vessel radius;    -   V—is the blood flow velocity vector within the vessel;    -   γ—is the relative angle between blood vessel direction and        tissue temperature gradient;    -   σ_(Δ)—is a shape factor term; and    -   q_(met)—is metabolic heat generation.

Knowledge of the thermal conductivity of the tissue can also be usefulin identifying and locating organs, vessels, ducts, etc. As can beunderstood from the above equation for determining thermal conductivity,as fluid flows through various tissue structures, the diameter of thestructure and the flow rate of the fluid therethrough affect the thermalconductivity of the tissue. The differences in thermal conductivitybetween the target tissue “T” and the surrounding organs, vessels,ducts, etc. may be used to locate and identify such structures. As willbe discussed in further detail below, these thermal conductivitymeasurements may be incorporated into modern imaging techniques toenhance the resulting images. A warning system (not shown) may beincorporated into electrosurgical system 100 to alert a user as probe200 approaches an organ, vessel, duct, etc. Theoretical and empiricaldata has shown that thermal conductivity, as opposed to electricalconductivity, may be better suited for identifying structures havinginstances of high flow rate therethrough.

3. Method of Using Electrical Conductivity

Knowledge of the electrical conductivity of the tissue permits a surgeonto adapt the treatment based on the electrical conductivity of thattissue. For example, a measurement of a relatively low electricalconductivity would indicate that, during therapeutic treatment oftissue, electrical energy would travel relatively less in the directionin which the relatively low electrical conductivity measurement was madeas compared to other directions Likewise, a measurement of a relativelyhigh electrical conductivity would indicate that, during therapeutictreatment of tissue, electrical energy would travel relatively more inthe direction in which the relatively high electrical conductivitymeasurement was made as compared to other directions.

Once the electrical conductivity of the target tissue “T” is determined,a selection of a suitable electrosurgical ablation needle, for example,associated power parameters, and relative orientations of ablationneedle placement may be determined, based thereon, for the thermaltreatment of said target tissue “T” by said electrosurgical ablationneedle.

The extent, level and/or direction of electrical conductivity may bealtered, varied and/or directed by increasing and/or decreasing thelevel of salinity in and around the target tissue.

The electrical conductivity of target tissue “T” may be continuouslyacquired throughout a thermal treatment procedure to continuouslymonitor the effect of the treatment on the target tissue “T” and thesurrounding tissue. Alternatively, the electrical conductivity may beacquired intermittently or between thermal treatments. In this manner,the tissue to return to normal or non-excited state prior to acquiringthe conductivity of the tissue, thereby minimizing the effect of thetreatment has on the conductivity values.

As with thermal conductivity, knowledge of the electrical conductivityof the tissue can also be useful in identifying local organs, vessels,ducts, etc. The differences in electrical conductivity between saidtarget tissue “T” and the surrounding organs, vessels, ducts, etc., maybe used to locate and identify such structures. Electrical conductivitymeasurements may also be incorporated into modern imaging techniques toenhance the image. A warning system (not shown) may be incorporated intoelectrosurgical system 100 to alert a user as probe 300 approaches anorgan, vessel, duct, etc. Theoretical and empirical data shows thatelectrical conductivity may be better suited for identifying structureshaving instances of low flow rate therethrough.

4. Method of Procedure Planning and Performing

In accordance with the present disclosure, as seen in FIGS. 4 and 5, anelectrosurgical system 400 may be used to plan, perform and/or evaluatethe effectiveness of thermal therapy procedures and the like. Accordingto a method of the present disclosure, electrosurgical device 210 and/orelectrosurgical device 310 are introduced into a target tissue “T” usingsuitable surgical techniques. For example, device 210 and/or device 310may be introduced into the target tissue “T” through percutaneousinsertion through the skin of the patient and may be monitored or guidedusing suitable imaging techniques (e.g., fluoroscopy, X-ray, CT scan,MRI). In one embodiment, electrosurgical devices 210, 310 are ablationneedles; however it is envisioned that the aspects of the presentdisclosure can be adapted for use with any suitable electrosurgicaldevice.

With electrosurgical device 210 and/or electrosurgical device 300positioned in the target tissue “T”, electrosurgical device 210 and/orelectrosurgical device 310 is/are activated, as described above, tosense, measure and/or otherwise determine a respective thermalconductivity and/or an electrical conductivity of the target tissue “T”.In an embodiment, where microprobe sensor 220 of device 210 is locatedon one side thereof or where sensor 320 of device 310 is located on oneside thereof, the respective thermal and electrical conductivities aremeasured in one particular direction (i.e., in the direction in whichsensors 220 and/or 320 are directed). Alternatively, sensing devices200, 300 may be used in a similar manner. Accordingly, in order topredict and/or plan a thermal therapy procedure, devices 210 and/or 310may be rotated along a longitudinal axis “X” thereof, by a known angle,in order to measure the values of the thermal and electricalconductivities of target tissue “T” at each of the rotated angles.

Once the values of the thermal and electrical conductivities of targettissue “T” at each of the rotated angles is measured, a determination ofthe type of electrosurgical treatment device, the energy deliveryparameters for the electrosurgical treatment device and/or theorientation of placement of the electrosurgical treatment device in thetarget tissue may be achieved. Such a determination is conducted inorder to maximize the desired and/or needed therapeutic effects of theelectrosurgical treatment device on the target tissue and to minimizeany undesired and/or un-needed therapeutic effects of theelectrosurgical treatment device on non-target tissue. As discussed infurther detail below, the thermal and electrical conductivity values mayalso be used in conjunction with other imaging modalities to enhance theresolution of the image.

In one method, devices 210 and/or 310 are rotated a full 360° in orderto measure the values of the thermal and electrical conductivities oftarget tissue “T” completely around devices 210 and/or 310. In onemethod, for example, the thermal and electrical conductivities of targettissue “T” may be measured and/or captured at approximately 90° angleswith respect to one another. It is contemplated that, as seen in FIG. 5,the thermal and electrical conductivities of target tissue “T” may bemeasured and/or captured at any suitable and/or desired angle “Θ”relative to one another.

In an embodiment, a portion of device 210, 310, disposed outside of thetarget tissue and/or outside of the body may be marked with indicia “I”(see FIG. 4) that is axially aligned with respective sensors 220, 320.In this manner, the location/orientation/direction of sensors 220, 320may be readily ascertained.

In one particular method, as seen in FIG. 5, devices 210, 310 may beinserted into target tissue “T” such that respective sensors 220, 320are oriented or directed toward a major blood vessel “V”. Thisparticular orientation may be identified as the 0° orientation or thelike. During the procedure, devices 210, 310 may be rotated about therespective longitudinal “X” axes to angles of approximately 90°, 180°and/or 270° relative to the 0° orientation.

Alternatively, an array of sensors may be placed facing the cardinaldirections on devices 210 and/or 310 such that rotation is notnecessary. Other array configurations would provide necessaryresolution.

The measured values of the thermal and electrical conductivities oftarget tissue “T” provide the directional attributes of the targettissue “T” to a suitable processor, such as a computer, including asuitable simulation and/or modeling environment. The measured and/orcaptured values of the thermal and electrical conductivities of targettissue “T” serve as input parameters in the computer simulation/modelingenvironment, such as, for example, E-Therm, COMSOL™, available fromCOMSOL, Inc., Burlington, Mass., etc. or any suitable finite elementmodeling program, neural network environment, or model-based predictivecontrol environment.

The measured values of the thermal and electrical conductivities oftarget tissue “T” would provide information about the target tissue “T”surrounding and/or in close proximity to devices 210, 310 that woulddetermine the differential directivities of thermal and/or electricalconductivities that would become a part of an initial condition of thecomputer simulation. The computer simulation may then predict anddisplay any non-uniform shape of the ablated coagulation zone as anumerical representation, a graphical representation, as an alarm thatimportant dimensions are not met, or any other suitable indicator.

A graphical representation may be available as an input to a medicalimaging device to be integrated into a medical image generated by anysuitable imaging method, as described above. This data representationmay be used for procedure planning by providing this essentialinformation about said target tissue “T” prior to or during treatment topredict the shape of the treated zone. Similar data representation mayalso be acquired and used following a treatment to evaluate theeffectiveness of the treatment. This predictive modeling with sensedconductivities may be used with suitable energy treatment modalitiesthat include and are not limited to RFA (e.g. Cool-Tip), microwaveantennas, cryoablation probes, and laser thermal devices.

As discussed above, the thermal and electrical conductivity values maybe used to enhance other imaging modalities. For example, conductivityvalues may be useful in highlighting the presence and location oforgans, vessels, ducts, etc. In this manner, a surgeon may plan andperform a procedure with a better understanding of said target tissue“T” and the location of critical structures in the area such that theymay be avoided during treatment. Additionally, viewing the imagesenhanced through use of the conductivity values may expose structurethat would otherwise have gone undetected. Conductivity values may alsobe useful in providing the degree of perfusion and/or vasculature in thetarget tissue.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of preferred embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended hereto.

Although the above description has detailed the aspects of the presentdisclosure with regards to medical treatment, this method of directionalconductivity measurement may apply to other fields of endeavor. Forexample, in the field of geology, this method could be used to detectsubterranean features such as the presence of water, oil, rock orgeological compositions.

1-5. (canceled)
 6. A method of enhancing an image, comprising the stepsof: measuring at least one of a thermal conductivity or an electricalconductivity of a target tissue in at least one direction; inputting atleast one of the measured conductivities of the target tissue for eachdirection into a modeling environment to create at least one resultingimage; and combining the at least one resulting image to produce anenhanced image.)
 7. The method of claim 6, wherein the imaginingtechnique includes at least one of fluoroscopy, X-ray, CT scan,ultrasound, or MRI.
 8. A method of enhancing a medical image,comprising: positioning a probe having a sensor in proximity to tissue,the probe defining a longitudinal axis; rotating the probe about thelongitudinal axis from a first rotational position to a secondrotational position different than the first rotational position;measuring, via the sensor, a conductivity of the tissue at each of thefirst and second rotational positions; inputting the measuredconductivities of the tissue into a modeling environment to generate afirst image; and enhancing a second image generated by an imaging devicebased on the first image.
 9. The method according to claim 8, furthercomprising generating the first image using the imaging device.
 10. Themethod according to claim 8, wherein the imaging device is selected fromthe group consisting of an ultrasound device, an X-ray device, and anMRI device.
 11. The method according to claim 8, wherein inputting themeasured conductivities of the tissue into the modeling environmentincludes generating at least two images.
 12. The method according toclaim 11, wherein enhancing the image of the tissue includes combiningthe at least two images.
 13. The method according to claim 8, furthercomprising identifying, within the enhanced second image, an anatomicalstructure in proximity of the tissue.
 14. The method according to claim8, wherein measuring, via the sensor, the conductivity of the tissueincludes measuring at least one of a thermal conductivity of the tissueor an electrical conductivity of the tissue.
 15. A method of enhancing amedical image, comprising: generating a first image using an imagingdevice; positioning a probe in proximity to tissue, the probe having asensor and defining a longitudinal axis; rotating the probe about thelongitudinal axis defined by the probe from a first rotational angle toa second rotational angle different than the first rotational angle;measuring, via the sensor, a conductivity of the tissue at each of thefirst and second rotational angles; inputting the measuredconductivities of the tissue into a modeling environment to generate atleast one second image; and enhancing the first image generated by theimaging device based on the at least one second image.
 16. The methodaccording to claim 15, wherein measuring, via the sensor, theconductivity of the tissue includes measuring at least one of a thermalconductivity of the tissue or an electrical conductivity of the tissue.17. The method according to claim 15, wherein rotating the probe aboutthe longitudinal axis defined by the probe includes maintaining theprobe in a straight configuration.
 18. The method according to claim 15,wherein inputting the measured conductivities of the tissue into themodeling environment includes generating at least two images.
 19. Themethod according to claim 18, wherein enhancing the first image includescombining the at least two images.
 20. A method of measuring tissueconductivity, comprising: positioning a probe having a sensor inproximity to tissue, the probe defining a longitudinal axis; rotatingthe probe about the longitudinal axis defined by the probe from a firstrotational angle to a second rotational angle different than the firstrotational angle while maintaining the probe in a straightconfiguration; and measuring, via the sensor, at least one of a thermalconductivity or an electrical conductivity of the tissue at each of thefirst and second rotational angles.